Neurobiology of injury (compression, traction, laceration) and repair, and grading of injuries
The functioning nervous system is an integrated system including conscious and subconscious pathways in the brain and spinal cord, the peripheral nerves, and specialized target organs. Efferent and afferent feedback pathways integrate at multiple levels, and there is interplay with mood, life function, growth, and development. The peripheral nervous system provides homeostatic and pain functions, and links the virtual world of our consciousness to the physical body that senses and manipulates the world around us. Injury disconnects the central nervous system from physical reality and induces profound, time-dependent changes at all levels of the system that mostly impede functional restitution after nerve reconstruction. For surgery to optimize outcomes it must be timely, and applied with precision, neurobiological awareness, and aided by adjuvant therapies or technologies that modulate responses within the central nervous system, primary motor and sensory neurons, repair site, distal nerve stump, and target organs.